Method of sharpening saws



I Nov. 10, 1942. E. J. HECHLER 2,301,539

METHOD OF SHARPENING SAWS Original Filed Dec. 17, 1940 Ernest J.Hechler.

Patented Nov. 10, 1942 METHOD OF SHARPENING SAWS Ernest J. Hechler,Troy, Mo. Original application November 8, 1938, Serial No.

239,582, now

Patent No. 2,224,867, dated December 17, 1940. Divided and thisapplication September 30, 1940, Serial No. 359,118

2 Claims.

This invention relates to saws of that general type shown and describedin my copending application filed in the United States Patent Office onthe 8th day of November, 1938, under Serial No. 239,582, and on whichLetters Patent No. 2,224,867, issued Dec. 17, 1940, the presentinvention being a division thereof.

The object of the invention is to provide a novel method or process offiling the teeth of the saw after said teeth have been sharpened and setwhereby the saw will cut through boards, logs and other lumber withminimum effort on the part of the operator and produce a smoothglasslike surface at the cut end of the lumber so as to render itunnecessary to subsequently plane or otherwise finish said cut end inorder to match the end of an adjacent strip of lumber.

The method consists in sharpening and setting the teeth of the saw,placing the saw on a fiat surface with one side of the saw in contacttherewith, positioning an abrasive tool against the sides of the setteeth near the points thereof and moving said tool longitudinally of thesaw to form alternate teeth on one side of the saw with beveled faces,reversing the position of the saw on said fiat surface and moving theabrasive tool longitudinally thereof and in contact with the set teethto bevel alternate teeth on the other side of said saw, and subsequentlychamfering the beveled faces of some or all of the teeth to form arelieved area extending transversely of the teeth for a portion of thewidth thereof.

In the accompanying drawing forming a part of this specification and inwhich similar numerals of reference indicate corresponding parts in allthe figures of the drawing:

Figure 1 is a side elevation of a portion of a saw blade constructed inaccordance with my improved method, the chamfered portions of the teethbeing omitted for the sake of clearness,

Figure 2 is a similar view on an enlarged scale showing the constructionof the teeth of the saw before being chamfered,

Figure 3 is a vertical sectional view taken on the line 3-3 of Figure 2.

Figure 4 is a side elevation of one of the saw teeth after the bevelededge thereof has been chamfered, and

Figure 5 is a transverse sectional view taken on the line 5-5 of Figure4.

The improved method or process forming the subject-matter of the presentinvention may be used in connection with cross cut saws, rip saws,circular saws or any other type of saw, and in Figure 1 of the drawing,there is illustrated a cross cut saw, in which 5 designates the blade,the teeth 6 of which are sharpened at 1 and set in the usual manner.

In carrying the invention into effect, I file or otherwise cut thesmooth face 8 of each tooth longitudinally thereof in the direction ofthe point 9 of the tooth to provide a beveled surface it! disposed at anangle to the set of the tooth and defining oppositely disposed cuttingedges H and !2. These cutting edges H and I2 operate on the lumber witha planing action when the saw is in use and produce a smooth glass-likesurface devoid of ridges, saw tooth markings and other irregularities.The beveled surface H3 preferably extends for approximately one-third ofthe length of the tooth, but it will, of course, be understood that thelength of the beveled surface is optional and may be varied according tothe conditions under which the saw is to be used. By reference to Figure1 of the drawing, it will be noted that, while the pointed end of eachtooth is provided with a beveled surface I0, said beveled surfaces arealternately disposed when the saw is Viewed in side elevation so thatthe edges thereof out through the lumber on both the up and down strokeof said saw. It will further be noted by reference to Figure 3 that thebeveled portion I0 is disposed substantially parallel to the verticalplane of the body of the blade 5, but the inclination of the bevel maybe varied if desired so that said bevel will be disposed at an angle tothe saw blade as well as to the set of the saw tooth, as indicated indotted lines in said figure.

One side of the beveled face lfl of each or all of the saw teeth iscurved. or chamfered, at [3, thereby forming a relieved area extendingtransversely of the tooth for a portion of the width thereof and somedistance back of its leading edge to assist in preventing wedging orsticking of the blade in the saw kerf during the sawing operation. Thischamfering of the beveled faces of the teeth is particularly applicableto rip saws or other saws having a one-Way out. It will, therefore, beunderstood that in certain types of saws the chamfered portions may beomitted if desired without departing from the spirit of the invention.

In treating a standard saw in accordance with my improved method orprocess, the teeth of the saw are first sharpened and set in the usualmanner. The saw is then supported on a table or other fiat surface withthe blade 5 in contact therewith, and by means of a file, emery wheelorother suitable tool the beveled portions l0 are formed on the teeth onone side of the saw by pressing the file or emery wheel flat against theteeth and moving said file longitudinally thereof. After the teeth onone side of the saw have been sharpened, the saw is reversed and thesame operation repeated on the teeth on the other side of the saw sothat the outer surfaces of alternate set teeth on both sides of the sawwill be provided with said beveled faces. The beveled faces of some orall of the saw teeth are then chamfered in the manner previouslydescribed,

thus forming a relieved portion extending trans- V versely of thebeveled face of the tooth so as to assist in preventing wedging orsticking of the blade in the saw kerf during the sawing operation, aspreviously stated.

A saw constructed in accordance with my improved method or process doesnot materially in' crease the cost of manufacture thereof while at thesame time provides a saw which is easy to operate and which will producea smooth cut in the lumber so as to render it unnecessary tosubsequently plane or otherwise finish the cut end or ends in order tomatch the end of an adjacent strip of lumber.

It will, of course, be understood that the improved method may be usedin connection with any type of saw and that the chamfered portions ofthe teeth may be formed either before or after said teeth are inclinedor beveled.

Having thus described the invention, what is claimed as new is:

1. The method of sharpening straight saws having triangular shaped teethprovided with beveled cutting edges and having the medial line of eachtooth extending substantially at right angles to the saw blade, saidmethod comprising sharpening and setting the teeth of the saw, placingthe saw on a fiat surface with one side of the saw in contact therewith,positioning an abrasive tool against the sides of the set teeth near thepoints thereof and moving said tool longitudinally of the saw to formalternate teeth on one side of the saw with beveled faces inclined inthe direction of the saw tooth points and intersecting said points andthe beveled cutting edges of the teeth, reversing the position of thesaw on said flat surface and moving the abrasive tool longitudinallythereof and in contact with ie set teeth to bevel alternate teeth on theother side of said saw in a like manner. 2. The method of sharpeningstraight saws having triangular shaped teeth provided with beveledcutting. edges and having the medial line ofeachtooth extendingsubstantially at right angles to the saw blade, said method comprisingsharpening and settnig the teeth of the saw, placing the saw on a fiatsurface with one side of the saw in contact therewith, positioning an arading tool against the sides of the set teeth near the points thereofand moving said tool longitudinally of the saw to form alternate teethon one side of the saw with beveled faces inclined in the direction ofthe saw tooth points and intersecting said points and the beveledcutting edges of the teeth, reversing the position of the saw on saidfiat surface and moving the tool longitudinally thereof and in contactwith the set teeth to bevel alternate teeth on the other side of saidsaw in a like manner, and subsequently chanifering one side of some orall of the teeth of the saw at the beveled faces thereof to providerelieved areas extending downwardly from the points of the teeth andinwardly transversely thereof for a portion of their width and somedistance back of the leading edges of said teeth.

ERNEST J. HECHLER.

